My 95 Grand Cherokee has developed a strange vibration. While driving on the Interstate or any other high everything is fine, however when I leave the Interstate and turn the front wheels approximately 10 degrees or more, something makes a thumping sound and seems to put the motor in a strain. When I straighten the wheels everything is OK, but if the wheels are turned in either directions the thumping starts. I have checked the CV joints and they are good. Outside of the vehicle I can not tell where the thumping is coming from and it is not easy to hear, but the thumping can be felt inside the vehicle, and seems to comefrom the rear part of the vehicle. The vehicle has to be driven at least 30 miles before this happens. Has this happened to others, if so what was the problem? Any ideas will be appreciated

I've got the same problem after highway driving. I was looking around the internet and on another forum, the consensus seems to be that it is the viscuous coupler going bad. It seems it has been a problem on the 93-98 Jeep Grand Cherokees. Several people reported the same problem. As I understand it, the VC has a bad seal problem and can leak Automatic Transmission fluid into the VC disrupting the fluid requirements for the VC. It works fine when the system is cool. But drive it on the highway and heat up the fluid, and you get the thumping that I get.

taterjeep,
This might well be my problem, it seem logical after looking at the Jeep transfer case diagrams. Have you corrected your problem? If so what is the solution? If not what do you plan to do? Do you have any idea how long it takes before the problem shows up driving on straight roads?